Signal.



A. G. CLARK.

SIGNAL.

APPLIOATIONIILED mum, 190a.

Patented sept. 10,1912.

3 SHEETS-SHEET 1.

1 I In AREA [3. CLARK- ATTY.

A. G. CLARK:

SIGNAL.

APPLIOATIONI'ILED JAN.27,1908.

Patented Sept. 10, 1912.

INVENTDR AREA B- E LARK ATT Y.

COLUMBIA PLQNOURAPH C0" WASHINGTON, D. c.

A. G. CLARK.

SIGNAL.

APPLICATION I'LPLED JAN.27, 1908.

Patented Sept. 10,1912.

F1 His.

3 SHEETS-SHEET 3.

INVENTEIR.

AREA 1E LARK M WITNEEEIEE W 67 ATTY COLUMBIA PLANDORAPH CQHWASHjNOTON. b, r.

UNITED STATES PATENT OFFICE.

ABBA G. CLARK, OF SCI-IENECTADY, NEW YORK, ASSIGNOR, BY MESNE ASSIGNMENTS,

TO THE UNION SWITCH AND SIGNAL COMPANY, A CORPORATION OF PENNSYL- VANIA.

To all whom it may concern.

Be it known that 1, ABBA G. CLARK, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Signals, of

which the following is a specification.

My invention relates to permissive block signals for electrically operated roads of a type in which a plurality of cars traveling in the same direction may be admitted to a block, each of the cars as it enters being counted by the signal mechanism, which is so arranged that the signals are notcleared until the last car has left the block.

The counting mechanism ordinarily employed in signals of this type comprises a ratchet-wheel and a pair of electro-magnets provided with pawls for moving the ratchetwheel step by step in opposite directions. These electro-magnets are energized respectively when a car enters and when a car leaves the block. A possibility of failure exists in signals of this type, unless special means are provided for guarding against it, because of the fact that both the countingin and counting-out magnets operate on the same ratchet-wheel, so that if the countingout magnet is energized by a car standing on the trolley contact connected to that magnet, the ratchet-wheel is locked by the magnet, so that if a car enters the block at this time, the counting-in magnet, though energized is unable to move the ratchet so as to count the car in.

The objectof my invention is to obviate the possibility of such a failure, and consists in so arranging the connection between the electro-magnets and the step-by-step device that the step-by-step device is disengaged from the operating magnet as soon as the magnet has shifted it, and is, therefore, free to be operated immediately by the other magnet whether or not the first magnet re mains energized. If the operating magnets in addition to shifting the ratchet-wheel, close electric contacts when energized, it is ordinarily necessary to provide means such as a dash-pot for retarding the return movement of the magnet cores in order that the contacts may remain closed a sufficient length of time to enable the lamps or other devices connected to the contacts to respond to the current. Furthermore, with certain types of trolley contacts, in which the cir- Specification of Letters Patent.

Application filed January 27, 1908.

SIGNAL.

Patented Sept. 10,1912.

Serial No. 412,721.

cuit of the magnets may be made and broken .important to provide means for releasing the ratchet-wheel from the magnet as soon as its stroke is completed, whether or not there is any liability ofthemagnet remainmg energized for any length of time, since otherwise, the operation of the ratchet-wheel by the other magnet might be prevented bV the retarding device of the first magnet. U

My invention comprises certain features which will be specifically pointed out in the appended claims, and which will best be understood by reference to the accompanying drawings, in which Figure 1 shows a front elevation of a signal arranged in accordance with my invention, with the door or cover removed; Fig. 2 shows a side elevation of the same with the casing in cross-section; Figs. 3 and 4 are detail views, partly in cross-section, of the ratchet-wheel and pawls; Fig. 5 is an enlarged detail view of one of the pawls; and Figs. 6' and 7 are details of other parts of the mechanism.

In the drawings, 1 represents the inclosing case, to which is secured the supporting member 2. Mounted on this member is a pair of electro-magnets 3. The cores 4 of these magnets are provided with pawls 5 pivotally mounted on the cores. Between the pawls isa ratchet-wheel 6, which is journaled in and wholly supported by an arm or bracket. 7 depending from the supporting member 2. The supporting member 2- thus carries all the parts of the signal operating mechanism, and maintenance of perfect alinement is assured. On the shaft of the ratchet-wheel 6 is a star-wheel 8 for holding the ratchet-wheel in position and preventing its being moved more than one step at a time. This star-wheel 8 is engaged by the usual pawl 9, which is pressed against the face of the star-wheel by its own weight and by the light spring 10. An arm 11 is fixed to the shaft of the ratchet-wheel, and, when the ratchet-wheel is in normal position, engages an arm 12, which is loosely mounted on theshaft of the ratchet-wheel. This arm '12 is connected through a strap 13 to a short crank 14, which carries on its shaft the light signal banner 15 placed behind a window 16 in the casing for giving the day-indication. As long as the block is clear and the ratchet-wheel and arm 11 stand in the position shown, the arm 12 is held raised, as shown in Figs. 1, 2 and 3. As soon as a car enters a block, and the lefthand magnet 3 in Fig. 1, which is the counting-in magnet, is energized, the ratchet wheel 6 is moved one step in a clockwise direction, as viewed in this figure, and the arm 11 is moved away from the arm 12,

.the arm 11 farther away from the arm 12.

As each car leaves the block, the countingout magnet, which is the right-hand magnet 3 in Fig. 1, is energized, and the ratchetwheel is returned one step in the opposite direction. As the last car leaves the block, arm 11 again engages arm 12, raising this arm to its normal position and restoring the banner 15 to its normal position. For the night-indication lamps 18 are provided. These lamps are shown in Fig. 2 mounted on the inside of the door of the casing behind the lens 19. There lamps may be controlled by any suitable contact arrange ment, not shown.

If it is desired to close any circuit momentarily for the operation of other signal mechanism when each magnet is energized,

a contact 20 may be placed on each pawl 5 and stationary contacts 21, shown in Fig. 2, may be arranged to be bridged by the contact 20. If such contacts are employed, they may be maintained closed for any desired length of time, when the magnet is energized, by means of dash-pot 22, the piston of which is connected to the core 4 of the electro-magnet.

In order to prevent the ratchet-wheel from being locked in position for any length of time by the continued energization of either magnet or by the action of the dashpot, I provide guiding means for each pawl such that it moves in different paths on its upward and downward strokes, and is moved out of engagement with the ratchet: wheel as soon as its upward stroke is completed. For this purpose I place on the pawl 5 a pin 23. When the magnets are deenergized the pawls are out of engagement with ratchet-wheel, as shown in Fig. 1. When one of the magnets is energized, the pawl moves upward until its pin 23 engages a fixed stud or, guide 24, which has an inclined face on the side toward the ratchetwheel, so as to move the pawl toward the ratchetwheel and into engagement with it, as shown in Fig. 3. In this figure the pawl is just engaging the ratchet-wheel, and is about to move it. As the upward movement of the pawl continues, the pin 23, strikes the lower side of the member 25, which is pivoted at 26, and is normally held in the position shown in Fig. 3 by gravity and by a light spring 27. The continued upward movement of the pawl 5 and the pin 23 rocks the member 25 on its pivot until the pin 23 comes into engagement with another fixed stud 28. At this point the ratchetwheel has been moved one tooth. The stud or guide 28 has an inclined surface, which guides the pin 23, so as to move the pawl away from the ratchet-wheel, as shown in Fig. 4, at the same time allowing the member 25 to drop back to its original position. The engagement of the pawl 5 with the ratchet (i is consequently only momentary, so that no matter how long the pawl is kept raised in the position shown in Fig. 4, either by the continued energization of its actuating magnet, or by the dash-pot, the ratchetwheel is not locked, but is free to be moved by the other magnet. When the magnet is de'e'nergized, the pawl drops slowly, retarded by the dash-pot; but the pin 23 is guided by the member 25 in a path which keeps it away from the ratchet-wheel and brings the pin into engagement with the upper or lefthand surface of the stud 24. The pin 23 travels down this surface until it reaches the bottom of the stud 24, and then swings back into the position shown in Fig. 1; its movement being limited by the pin 29 on the pivoted member 25, which engages a flange on the pawl, as is most clearly shown in Figs. 1 and 5.

If it is desired to limit the number of cars entering a block to a smaller number than that provided for by the number of teeth on the ratchet-wheel, or if it is desired to give an indication when that number is reached, the desired result may be accomplished by the arrangement shown in Figs. 6 and 7. A disk 30 is fixed on the shaft of the ratchet-wheel, and has near its periphery a number of holes corresponding to the number of teeth on the ratchet-wheel. Pin 33, shown in Fig. 6, may be inserted in any one of these holes. Arm 31 is loosely mounted on the shaft of the ratchet-wheel, and normally rests against the fixed stop 32. When the disk 30 has been rotated a certain number of steps, dependent on the position of the pin 33, this pin engages the lower side of the arm 31, and raises it. This arm carries at its end a contact 34, which, when the arm is raised, bridges the stationary contacts 35, shown in Figs. 1 and 2. The circuit thus completed may be employed to give a suitable indication that the block is occupied by the maximum number of cars allowed therein.

What I claim as new, and desire to secure by Letters Patent of the United States, 1s,

1. In combination, a step-by-step device, a signal controlled thereby, an electro-magnet, operative connections between the core of said magnet and said device whereby the movement of said core in one direction moves said device a step, means for disengaging said core from said device after it has been moved, and means for retarding the return movement of the core.

2. In combination, a step-by-step device, a signal controlled thereby, an electro-magnet, operative connections between the core of said magnet and said device whereby the movement of said core in one direction moves said device a; step, means for disengaging said core from said device after it has been moved, means for retarding the return movement of the core, and electric contacts controlled by said core.

3. In combination, a ratchet-wheel, a signal controlled thereby, an electro-magnet, a pawl actuated by the core of said magnet and adapted to engage and move said ratchetwheel a step upon the movement of the core in one direction, means for guiding said pawl out of engagement with said ratchetwheel when it has been moved, and means for retarding the return movement of said core.

4. In combination, a ratchet-wheel, a signal controlled thereby, an electro--magnet, a pawl actuated by the core of said magnet and adapted to engage and move said ratchet-wheel a step upon the movement of the core in one direction, means for guiding said pawl out of engagement with said ratchet-wheel when it has been moved, means for retarding the return movement of said core, and electric contacts controlled by said core.

5. In combination, a ratchet-wheel, a signal controlled thereby, an electro-magnet, a pawl actuated by the core of said magnet and adapted to engage and move said ratchet-wheel a step upon the movement of the core in one direction, means for guiding said pawl out of engagement with said ratchet-wheel when it has been moved, means for retarding the return movement of said core, and guiding means for keeping said pawl out of engagement with the ratchet-wheel on the return movement of the pawl.

6. In combination, a ratchet-wheel, a signal controlled thereby, an electro-magnet, a pawl actuated by the core of said magnet and adapted to engage and move said ratchet-wheel a step upon the movement of the core in one direction, means for guiding said pawl out of engagement with said ratchet-wheel when it has been moved, means for retarding the return movement of said core, guiding means for keeping said pawl out of engagement with the ratchet-wheel on the returnmovement of the pawl, and electric contacts controlled by the movement of the core.

7. In combination, a ratchet-wheel, a signal controlled thereby, an electro-magnet, a pawl actuated by the core of the magnet and adapted to engage and move said ratchet-wheel a step upon the movement of the core in one direction, guiding means for the pawl for causing it to move in different paths on its forward and return strokes, whereby the pawl engages the ratchet-wheel only when moving in one direction, and means for retarding the return movement of the pawl.

8. In combination, a ratchet-wheel, a signal controlled thereby, a pair of electromagnets for moving said wheel in opposite rections, a pair of pawls actuated by the cores of said magnets respectively and each adapted to move said ratchet-wheel a step upon the movement of its actuating core in one direction, and guiding means for each pawl for causing it to move in different paths on its forward and return strokes, whereby the pawl engages the ratchet-wheel only when moving in one direction.

9. In combination, a ratchet-wheel, a signal controlled thereby, a pair of electro-mag nets for moving said wheel in opposite di rections, a pair of pawls actuated by the cores of said magnets respectively and each .adapted to move said ratchet-wheel a step upon the movement of its actuating core in one direction, guiding means for each pawl for causing it to move in different paths on its forward and return strokes, whereby the pawl engages the ratchet-wheel only when moving in one direction, and means for retarding the return movements of the pawls.

In witness whereof, I have hereunto set my hand this 25th day of January, 1908.

ABBA G. CLARK. Witnesses:

HELEN ORroRD, BENJAMIN B. HULL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, I). G. a 

